Method for separating rosette plants

ABSTRACT

A method for separating a lump piece of rosette plants. The method includes the steps of gripping a rosette plant and positioning it parallel to a longitudinal axis of an elongated holder which has a longitudinal opening at least along the longitudinal axis; introducing a part of the lump piece of the rosette plant into the holder via the mentioned longitudinal opening; cutting off the lump piece along a cutting plane parallel to the longitudinal axis, while closing the longitudinal opening, such that the introduced part of the lump piece is enclosed in the holder; and removing the enclosed cut-off part of the lump piece from the holder. The method includes the further step of cutting off a part of the rosette plant enclosed in the holder along a second cutting plane.

The invention relates to a method and apparatus for separating a lumppiece of rosette plants. Such a method and apparatus are used during theasexual multiplication (propagation by cuttings) of rosette plants.

A rosette plant is roughly built up from a basis of growing points fromwhich new leaves and roots grow. In an adult plant, this basis isrelatively large in size and comprises a large number of sproutedleaves. By placing a part of the rosette plant in a specific medium,growing points or other plant parts can be incited to form shoots. Inthis manner, a lump piece of rosette plants is formed, designated belowas “lump piece”. The asexual multiplication takes place by cutting thislump piece into parts and placing the individual parts on a growingmedium. These parts form new shoots, which again form a new lump piece,so that a multiplication process results, which can be repeated severaltimes. In this manner, many, up to as many as thousands of, copies canbe cultured from one single plant. This process is referred to as plantmultiplication.

Although this process is substantially relatively simple in nature, thepractical conditions in which the process is carried out are of greatimportance to be able to realize a sufficiently large and germ-freeyield. It is crucial, then, to check the ambient conditions; inparticular, it is important that the multiplication nearly always takesplace sterilely. In addition, the separation of the lump piece isrelatively difficult, because the lump often has a diverging shape andsize, and because it is of importance to damage growing points as lessas possible. A damaged cutting will show a decreased growth on thedamaged parts, so that the occurrence of damage during separation has arelatively large negative effect on the yield. These problems haveresulted in that contrary to automated multiplication techniques forother types of plants, such as stem plants, for rosette plantssatisfactory techniques enabling the multiplication to be carried outautomatically have not been developed as yet.

The invention has for its object to remove these problems and to providea method and apparatus with which automated processing is possible. Thisobject is achieved by a method of the type referred to in the openingparagraph, which further comprises the steps of gripping a rosette plantand positioning it parallel to a longitudinal axis of an elongatedholder, which comprises a longitudinal opening at least along thelongitudinal axis; introducing a part of the lump piece of the rosetteplant into the holder via the mentioned longitudinal opening; cuttingoff the lump piece along a cutting plane parallel to the longitudinalaxis while closing the longitudinal opening, such that the introducedpart of the lump piece is enclosed in the holder; and removing theenclosed cut-off part of the lump piece from the holder.

It is observed that the introduction of plant material into a holder isknown from the International application WO 91/18499. This application,however, relates to the multiplication of stem plants in which a singlenode is pressed through a circular cut in the holder. This method,however, is in no way transferable to the culture of rosette plants,because here the individual nodes cannot be identified, but are growntogether into one lump shaped part.

Because the method makes use of the enclosure of the plant in a holderunder simultaneous separation thereof, in the holder a cutting isenclosed which is relatively uniform in size and can relatively easilybe processed further from this holder.

In a preferred embodiment, the method comprises the further step ofcutting a cut-off part of the rosette plant enclosed in the holder alonga second cutting plane. In particular, this is important in themultiplication phase in which the sprouting stems are cut off.

In a further preferred embodiment, the removal from the holder can takeplace while retaining orientation. Thus, it can be effected, forinstance, that the cut-off cutting is introduced into a growing mediumin the right orientation, that is to say with the sprout points in adirection remote from the growing medium.

In another preferred embodiment, the cutting off of the lump piece iscarried out by the rotation of two half-round sections engaging eachother along a longitudinal axis, during which the sections cuttinglyglide along each other, such that after rotation the sections form acylinder in which the part of the lump piece is received. It is observedthat such cutting sections are known per se, for instance from U.S. Pat.No. 5,843,106. This application, however relates to an apparatus fortaking biopts from human tissue.

In a further embodiment, the method comprises the blowing out of thecut-off part of the lump piece enclosed in the holder, by means ofcompressed air.

The application further relates to an apparatus for separating the lumppiece of rosette plants, comprising: an elongated holder which comprisesa longitudinal opening at least along the longitudinal axis; and a firstcutting element for cutting off a lump piece along a cutting planeparallel to the longitudinal axis while closing the longitudinalopening, such that an introduced part of the lump piece is enclosed inthe holder.

The apparatus may comprise a computer-controlled gripper for positioningthe rosette plant. In a semi-automated embodiment, it is also possible,however, that the rosette plants are manually introduced into theapparatus, or that a person manually introduces the cutting places orthe location of the shoots on the plant into the system. A furtherembodiment relates to an apparatus which comprises a transverse openingoriented transversely to the longitudinal axis. This transverse openingcan be used to axially introduce the lump piece into the apparatus.Alternatively, the lump piece may be introduced radially, via thementioned longitudinal opening. A combination of both directions is ofcourse also possible. In addition, the apparatus may comprise a secondcutting element for cutting off a cut-off part of the rosette plantenclosed in the holder along a second cutting plane transverse to thelongitudinal axis while closing the transverse opening.

The holder may have such a cross-section that in enclosed condition thecut-off part is clampingly enclosed, so that upon removal a cut-off partretains its orientation.

In a preferred embodiment, the elongated holder comprises a firsthalf-round section, and the cutting element comprises a secondhalf-round section, which first and second sections engage each otheralong a rotation axis and carry out a cutting movement upon rotation,such that after rotation the sections form a cylinder in which a part ofa cut-off lump piece can be received.

The apparatus may comprise an expelling element for removing theenclosed cut-off part of the lump piece from the holder. Furthermore,the expelling element may be arranged to expel the cut-off part alongthe longitudinal axis of the holder. Advantageously, the expellingelement comprises an outflow longitudinal opening oriented along thelongitudinal axis of the holder for blowing out compressed air. Theoutflow longitudinal opening may be provided in the second cuttingelement, so that the cutting element, after having carried out a cuttingmovement, positions the outflow longitudinal opening such that thecut-off part can be blown out. The second cutting element may beconnected with a pair of parallel-arranged leaf springs.

The invention further relates to an automated culturing apparatus, inwhich an apparatus according to one of the above-mentioned aspects isincluded, and further comprising image recognition means for identifyinga rosette plant to be multiplied;

a gripper for gripping the rosette plant and positioning it;

an apparatus according to one of the above-mentioned aspects, which cutsoff and encloses the plant under control of the image recognition means;

transport and manipulation means for transporting and manipulating thegrowing medium, into which the cut-off cutting is introduced;

control means for controlling the gripper, the apparatus according toone of the above-mentioned aspects, and the transport and manipulationmeans under control of the image recognition means.

The invention will be explained in more detail with reference to thedrawing.

In this drawing:

FIG. 1 shows a system structure of an automated culturing systemaccording to the invention;

FIG. 2 shows a first embodiment of the apparatus according to theinvention;

FIG. 3 shows a schematic detailed representation of the rotating knivesin FIG. 2;

FIG. 4 shows a schematic detailed representation of a second knifeplaced transversely to the rotating knives;

FIG. 5 shows an alternative embodiment of the apparatus according to theinvention; and

FIG. 6 shows a second alternative embodiment of the apparatus accordingto the invention.

In the Figures similar or corresponding parts are indicated by the samereference numerals.

FIG. 1 shows an automated culturing system 1 for culturing rosetteplants according to the invention. The apparatus is built up from anelongated holder 2 and a cutting element 3. The holder 2 has alongitudinal opening (which is not visible in the Figure, because it isclosed by the cutting element 3), as will be explained in more detailwith reference to FIGS. 3, 5, and 6. The cutting element 3 is arrangedto cut off a lump piece while enclosed in the holder 2, as shown inFIG. 1. Meanwhile, the lump piece is held by a gripper 4, which grips,for instance, the stems 5 of a lump piece 6. The gripper 4 is controlledby a central processor 7, which is coupled with an image recordingsystem 8 for identifying a lump piece 6 to be cut off and for carryingout a relative movement of the lump piece 6 and the holder 2, so thatthe lump piece 6 can be introduced into the holder 2.

Before introducing the lump piece 6 into the holder 2, it is taken up bythe gripper 4 from a conveyor belt 9, on which trays 10 are placed witha growing medium (not shown), in which lump pieces 6 to be separated aregrown.

The lump piece 6 is positioned parallel to the holder, that is to say,an axis running from the growing points to the leaves runs substantiallyparallel to the longitudinal axis of the holder 2. The lump piece 6 isthen introduced into the holder 2 in a radial movement. If in the caseas shown in FIG. 1 the holder has a transverse opening 11, the lumppiece can also be introduced via an axial movement, or by a combinationof both movements. Alternatively, the lump piece may be fixed, and theholder may be manipulated so as to introduce the lump piece into theholder.

All this takes place under control of the processor 7 while fed bysignals from the image recording device 8. If the lump piece ispositioned in the holder in the right manner, it is cut off by thecutting element 3 parallel to the longitudinal axis of the holder 2while closing it, so that the introduced part 12 of the lump piece 6 isenclosed in the holder 2. It is observed that in this connection theterm “enclosing” means that the holder, optionally in combination withthe cutting element, forms an enclosure for the cut-off lump piece. Itis not important, then, if the lump piece 6 is held in the holder 2completely around, optionally in combination with the cutting element 3,that is to say along a longitudinal circumference of a plane transverseto the longitudinal axis of the holder 2. It is sufficient that theholder 2, in combination with the cutting element 3, can hold the lumppiece, preferably in an orientation retaining manner. The apparatus 1shown in FIG. 1 further comprises an expelling device in the form of acompressed air device 13, which is connected by a hose 14 with a nozzle15. After cutting off the lump piece 6, the nozzle 15 is located abovethe holder 2, so that by blowing compressed air through the nozzle 15,the cut-off lump piece 16 can be blown out parallel to the longitudinalaxis of the holder 2 at the bottom side. By properly dimensioning theholder 2, the lump piece 6 can be blown out while retaining orientation.As a result, it lands in a collecting tray 17 moved below the holder 2,in which it can be introduced into a growing medium (not shown) in theright orientation. The collecting tray 17 is moved on by a conveyor belt18, preferably under control of the processor 7.

In the preferred embodiment shown in FIG. 1, the nozzle is formed on asecond knife 19, which can cut off the stems from the lump piece 6,after it has been enclosed in the holder. The second knife 19 moves in acutting plane oriented transversely to the longitudinal axis of theholder 2 and is also controlled by the processor 7.

Referring to FIGS. 2 and 3, a preferred embodiment of the holder 2 shownin FIG. 1 will now be discussed in more detail. This holder 2 is formedby two half-round sections 20 and 21 engaging each other. The sections20, 21 may be identical in form, that is to say different only in size,with an inner section having a smaller cross-section than an outersection. In this connection, it is observed that in this embodiment theholder 2 and the cutting element 3 may actually have the sameappearance. In addition, it is so that a section 20 may be fixedlyprovided with a sharp edge 22 along a longitudinal side, optionally incombination with the second section 21, which may also be provided witha sharp edge 23. Furthermore, it may be that only one of both sections20 or 21 has a sharp cutting edge, while it is even possible that theholder and the cutting edge are fixedly formed on one of the parts, andthat the “cutting element” itself only performs a pushing function forpushing the root lump against a sharp edge of the holder. Such variantsare also considered to fall within the scope of protection of theclaims. According to FIGS. 2 and 3, the sections 20, 21 are designedsuch that they carry out a rotation relative to each other, whilecuttingly gliding along each other, after which rotation a cylinder 24is formed, in which the part of the lump piece 6 is received.Preferably, the sections are open on the transverse sides 25, so thatthe formed cylinder 24 is open. As a result, the cut-off lump piece canbe axially removed from the cylinder. Optionally, the lump piece to becut off may be axially introduced into the half-round sections 20, 21.

As shown in FIG. 2, the inner section 21 and the outer section 20 may bemounted on different holder plates 26 and 27. One plate 26 may beresiliently designed, for instance with parallel leaf springs 28. Thus,an axial movement of section 20 relative to section 21 can be effectedduring the rotation of the sections 20, 21. As a result, a purer cut canbe obtained, which, in view of the nature of the material, is of greatimportance to the yield.

Referring to FIG. 4, a preferred embodiment of the second knife 19 willnow be discussed, which moves in a cutting plane transverse to thelongitudinal axis of the holder 2 and/or sections 20, 21. The knife 19comprises a flat cutting plate 29, which is also mounted on a set ofleaf springs 30, which are oriented parallel. By carrying out a pushingmovement transversely to the leaf springs, by means of, for instance, atranslating arm (not shown), the cutting plate 29 can be moved intransverse direction and be brought above the holder 2, in a manner ascan be derived from FIG. 2. Provided in the cutting plate 29 is anopening 31, to which a nozzle 15 is connected, see FIG. 2. At a positionarranged above the holder 2, compressed air can be blown out of thecompressed air device 13 through the nozzle 15, under control of theprocessor 7. The cut-off lump piece 16 can thus be axially removed fromthe holder 2, preferably while retaining orientation.

Finally, FIGS. 5 and 6 show alternative embodiments of the holder andthe cutting element. These embodiments relate to a substantiallysymmetrically designed combination of a holder/cutting element in theform of two correspondingly formed U-shaped sections 32 and 33 with asharp longitudinal side. By laying the root lump along one of thesections 32 or 33 and blanking the other on, over, or in it, a part ofthe lump is cut off and enclosed in the elongated sections 32 and 33. Ina manner similar to that discussed with reference to FIGS. 1-4, theenclosed part can be removed from the sections and be placed in agrowing medium. Finally, FIG. 6 shows a tong structure 34, which can bemechanically or optionally manually operated, to move the sections 32and 33 toward each other. Such a tong structure is—slightly modified—ofcourse also possible to operate the rotating sections shown in FIGS. 2and 3.

The invention is not limited to the exemplary embodiments shown in theFigures, but may comprise all kinds of variations and modificationsthereof. For instance, in the exemplary embodiments the lump piece ismoved to the holder. Of course, arrangements are also possible in whichthe holder is moved to the lump piece. Furthermore, the invention is notonly limited to rosette plants in the strictly biological sense, butalso comprises a method and apparatus for plants which, in a specificculturing stage, possess a similar rosette plant structure, that is tosay, a basis of growing points from which new leaves and roots grow,which basis can be multiplied by splitting. Such variations areconsidered to be within the scope of the invention as defined by thefollowing claims.

1. A method for separating a lump piece of rosette plants, comprisingthe steps of: gripping a rosette plant and positioning it parallel to alongitudinal axis of an elongated holder, which comprises a longitudinalopening at least along the longitudinal axis; introducing a part of thelump piece into the holder via the mentioned longitudinal opening;cutting off the lump piece along a cutting plane parallel to thelongitudinal axis, while closing the longitudinal opening, such that theintroduced part of the lump piece is enclosed in the holder; andremoving the enclosed cut-off part of the lump piece from the holder. 2.A method according to claim 1, characterized in that the methodcomprises the further step of cutting off a cut-off part of the rosetteplant enclosed in the holder along a second cutting plane.
 3. A methodaccording to claim 1, characterized in that the removal from the holdertakes place while retaining orientation.
 4. A method according to claim1, characterized in that the cutting off of the lump piece is carriedout by the rotation of two half-round sections engaging each other alonga rotation axis, during which the sections cuttingly glide along eachother, such that after rotation the sections form a cylinder in whichthe part of the lump piece is received.
 5. A method according to claim1, characterized in that the method comprises the further step ofblowing out the cut-off part of the lump piece enclosed in the holder bymeans of compressed air.
 6. An apparatus for separating a lump piece ofrosette plants, comprising: an elongated holder which comprises alongitudinal opening at least along the longitudinal axis; and a firstcutting element for cutting off a lump piece along a cutting planeparallel to the longitudinal axis, while closing the longitudinalopening, such that an introduced part of the lump piece is enclosed inthe holder.
 7. An apparatus according to claim 6, characterized in thatthe apparatus comprises a transverse opening which is orientedtransversely to the longitudinal axis.
 8. An apparatus according toclaim 7, characterized in that the apparatus comprises a second cuttingelement for cutting off a part of the rosette plant enclosed in theholder along a second cutting plane transversely to the longitudinalaxis, while closing the transverse opening.
 9. An apparatus according toclaim 6, characterized in that the holder has such a cross-section thatin enclosed condition the cut-off part is clampingly enclosed, so thatupon removal a cut-off part retains its orientation.
 10. An apparatusaccording to claim 6, characterized in that the elongated holdercomprises a first half-round section, and that the cutting elementcomprises a second half-round section, which first and second sectionsengage each other along a rotation axis and, upon rotation, carry out acutting movement, such that after rotation the sections form a cylinderin which a part of a cut-off lump piece can be received.
 11. Anapparatus according to claim 10, characterized in that the sections arearranged to carry out an axial movement relative to each other duringthe rotation.
 12. An apparatus according to claim 6, characterized inthat the apparatus comprises an expelling element for removing theenclosed cut-off part of the lump piece from the holder.
 13. Anapparatus according to claim 12, characterized in that the expellingelement is arranged to expel the cut-off part along the longitudinalaxis of the holder.
 14. An apparatus according to claim 13,characterized in that the expelling element comprises an outflowlongitudinal opening oriented along the longitudinal axis of the holderfor blowing out compressed air.
 15. An apparatus according to claim 14,characterized in that the outflow longitudinal opening is provided inthe second cutting element, so that the cutting element, after havingcarried out a cutting movement, positions the outflow longitudinalopening such that the cut-off part can be blown out by means ofcompressed air.
 16. An apparatus according to claim 8, characterized inthat the second cutting element is connected with a pair ofparallel-arranged leaf springs.
 17. An automated apparatus, comprising:image recognition means for identifying a rosette plant to bemultiplied; a gripper for gripping the rosette plant and positioning it;an apparatus according to claim 6, which cuts off and encloses theplant; transport and manipulation means for transporting andmanipulating the growing medium, into which the cut-off cutting isintroduced; and control means for controlling the gripper, theapparatus, and the transport and manipulation means under control of theimage recognition means.